This is a bit of a misconception! Hawaii is actually located in the middle of the Pacific Plate, not at a plate boundary.

However, Hawaii's volcanic activity is caused by a "hot spot". This is an area where unusually hot magma rises from deep within the Earth's mantle, creating a plume of molten rock. As the Pacific Plate moves over this stationary hot spot, the magma breaks through the surface, forming volcanoes.

So, while Hawaii is not at a plate boundary, it's directly above a hot spot, which is responsible for its volcanic nature.